1. Field of the Invention
The present invention relates to a seat back for a vehicular seat.
2. Description of the Related Art
The seat back for the vehicular seat generally includes a seat back frame and a pad. Moreover, the seat back of the type having a thin pad further includes a plate member for supporting the back of the pad, and an elastic support mechanism for holding the plate member elastically and movably forward and backward relative to the seat back frame. The plate member of the prior art is disclosed in U.S. Pat. No. 6,296,308 (308 patent), for example. These plate members are formed into a substantially rectangular shape. And the portion for supporting the lumber of the passenger seated on the vehicular seat is made wider than the remaining portions.
However, there is a need in the art for a plate member and an elastic support mechanism that provides additional support for a user, thus resulting in a more comfortable use.